The effect of these and other recent polls is to lower my estimated approval to 35.9%., down over 6 percentage points since the new year began. A new low (with apologies to MP!) The difference between MPs analysis of change in the individual polls and mine is that I'm accumulating the evidence across all polls, and collectively they are implying that the "true" level of support continues to fall. I've written previously on the problem of spacing between polls here. At this point, President Bush's approval is falling 1% each 12.5 days, the most rapid decline of his presidency. If a poll has a 3% margin of error, we'd only observe a statistically significant change in that poll over a 38 day interval. Hence most changes in polls taken only a week or two apart are not statistically significant even if they are following the same rate of decline. The accumulated evidence across all the polls is a better estimate of the trend in approval, and is reflected in my blue trend line in the figure. Even so, day-to-day movements are not statistically significant, so I agree with MP that it probably shouldn't be headline news that a "new low" has been reached every day, simply because the trend is continuing down. By definition if the trend is down and you've passed the previous low, then every day is a "new low". Perhaps better to focus on the trend than the new record lows.

The President began a new series of speeches this week aimed at shoring up support for the Iraq war and his leadership. That tactic worked well in November and December, underscoring the importance of a positive message to move public opinion. Since the new year began, the messages from Washington and a series of events has been overwhelmingly negative for the White House. In November and December, the White House won the news cycle pretty consistently, and to good effect. They have not, so far, been able to sustain that performance in 2006. This week's beginning of a new offensive will test their ability to do so.

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About Me

I am co-founder of Pollster.com and founder of PollsAndVotes.com.
I am also a professor of political science at the University of Wisconsin, where I teach statistical analysis of polls, public opinion and election results. Data visualization is central to my approach to analysis.
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